Recent vehicles are equipped with various systems such an audio system for music reproduction and a navigation system for destination guidance. Some systems adjust a scale and move a cursor on a display screen. For example, when a rotation operation is performed on a dial type input device, an audio system adjusts a scale (sound volume) according to an operation amount of the rotation operation. When a finger slide operation is performed on a touch pad, a navigation system moves a destination selection cursor on a display screen.
In a vehicle, driver's finger or hand movement may become shaky due to an external factor such as a vehicle vibration, and the scale adjustment or the cursor movement on the screen may become unstable. For example, the unstable operation amount of the rotation operation may make adjustment to an intended sound volume difficult in some cases, and the unstable operation amount of the slide operation may make the positioning of the cursor difficult in some cases.
There is a proposed technology (Patent Literature 1) that uses a low pass filter to remove an external factor causing the scale adjustment and cursor movement to become a shaky motion and thereby smooth the scale adjustment and cursor movement.
Patent Literature 1: JP H08-137608A